Process for preparing polyesters improved in dyeability

ABSTRACT

IN WHICH R1 and R2 are each as defined above and p and q are each zero or a positive integer not more than 10, or blending the resultant polymer into linear fiber-forming polyesters. Process for preparing polyesters improved in dyeability with acid dyes which comprises polycondensing a dicarboxylic acid with a glycol, the whole or part of the glycol being the one represented by the formula: WHEREIN R1 and R2 are each a lower alkyl group or, when taken together, they represent a lower alkylene group, R3 is a lower alkyl group or a group of the formula:     D R A W I N G

United States Patent [72] Inventors Hldeakl Munakata;

Kazoo Watanabe; Yoshlkazu Arlmats'" Masakazu Tanaka, all 0! Otau-shl, Japan [2|] Appl. No. 885,964 [22] Filed Dec. 17,1969 [45] Patented Nov. 30, 1971 [73] Assignee Toyo Bose-kl Kabushl Kalsha Osaka-shl, Osaka-In, Japan [32] Priority Dec. 23, 1968 [33] Japan 31 43/9468!) [54] PROCESS FOR PREPARING POLYESTERS IMPROVED lN DYEABILITY 2 Claims, No Drawings 7 [52] U.S. Cl 260/860, 260/75 N [51 1 Int. Cl C08g 17/06, C08g l7/08, 6053370 4 [50] Field of Search 260/75 N, 860

[56] References Cited UNITED STATES PATENTS 2,739,958 3/1956 Lincoln et al 260/75 3,065,207 I l/l962 Andres 260/75 2,759,946 8/1956 Cislak et al. 260/297 Primary Examiner--Melvin Goldstein Attorney-Wenderoth, Lind & Ponack ABSTRACT: Process for preparing polyesters improved in dyeability with acid dyes which comprises polycondensing a dicarboxylic acid with a glycol, the whole or part of the glycol heing the one represented by the formula;

wherein R, and R are each a lower alkyl group or, when taken together, they represent a lower alkylene group, R is a lower alley [group or a group of the formula:

each zero or a positive integer not more than 10, or blending the resultant polymer into linear fiber-forming polyesters.

PROCESS FOR PREPARING POLYESTERS IMPROVED IN DYEABILITY The present invention relates to a process for preparing polyesters improved in dyeability with acid dyes. It also relates to a processfor preparing polyesters bearing a tertiary amino group.

Aromatic linear polyesters such as polyethylene terephthalate have broadly been used as fibers and films owing to their excellent physicochemical properties. But, those polyesters are difficulty dyeable, particularly with acid dyes. In order to improve such difficult dyeability, there has been proposed the introduction of a tertiary amino group to be served as the dyesite into them. Thus, the polycondensation of a dicarboxylic acid with a glycol, the whole or part of the dicarboxylic acid or the glycol being the one bearing a tertiary amino group, or the blending of the resulting polymer into polyesters affords easily dyeable polyesters. However, most of tertiary amino groupbearing compounds are not sufficiently stable to heat, especially in the presence of polyesters, and make occasionally colored the resultant polyesters.

It has now been found that tertiary amino group-containing glycols of the formula:

represent a lower alkylene group (e.g., tetramethylene, pentamethylene), R is a lower alkyl group (e.g.. methyl, ethyl, propyl, isopropyl butyl) or a group of the formula:

in which R and R are each as defined above and p and q are each zero or a positive integer not more than 10 are per se quite stable to heat and very hardly decomposed on the meltextrusion of polyesters incorporated therewith as the glycol component. Thus, the introduction of the said glycols into polyesters provides polymers, of which the shaped products are materially not colored and have excellent affinity to acid dyes. The present invention is based on this finding.

A basic object of the present invention is to embody linear polyesters improved in dyeability with acid dyes. Another object of this invention is to embody polymers useful as modifiers for improving the affinity to acid dyes of polyesters. A further object of the invention is to embody a process for preparing linear polyesters having a good affinity to acid dyes. These and other objects will be apparent to those conversant with the art to which the present invention pertains from the subsequent description.

The glycol [11 used as the source material for introduction of a tertiary amino group in the present invention may be prepared by various methods, of which typical ones are shown in the following scheme:

Preparation of the glycol [Iz p=q=0; R1=lower alkyl]:

Preparation of the glycol [I: p or 41 01:

wherein X is a halogen atom (e.g., chlorine, bromine) and R,, C. in 2 to 3 hours. The polymerization reaction is normally ef- R,, R p and q are each as defined above. fected at 200 to 270 within several hours.

According to the present invention, the polyesters improved lnan alternative way, the polymer M may be produced by in the afi'inity to acid dyes can be obtained by either one 01 the direct esterification of the glycol [l] with the dicarboxylic following two processes: 5 acid. In this case, the reaction is usually carried out by heating A. copolymerization process a mixture of the glycol [11 and the dicarboxylic acid, the

In the production of polyesters from dicarboxylic acids or former being employed in an equal amount to the latter or in their lower alkyl esters and glycols by conv nti nal slightly excess, at a temperature from 170 to 260 C. in an procedures such as ester exchange process and direct esterifiinert atmosphere (e.g., nitrogen) while elimination of the cation process, the glycol [11 is used as the whole or part of the b d d water f h reaction system, Aft rh d glycol component 50 th he polye te ha ng the residue of tion of water ceases, the atmosphere is reduced, and the the glycol [11 in the middle of or at the terminal of the polymerization is effected in the presence of the polymerizamolecule chain are produced. Although it is difficult to tion catalyst. copolymerize the glycol [l] in a large ratio since its reactivity In another alternative way, the polymer M may be produced is considerably lower than that of ethylene glycol or other al- 15 by reacting the glycol [11 with the dicarboxylic acid halide, kylene glycols, the obtained polyesters are dyeable in pale or preferably acid chloride. The reaction is ordinarily executed mediate colors with acid dyes. by mixing well a solution of the glycol [l] in aqueous alkali B. Blending process hydroxide with a solution of the dicarboxylic acid halide in an The incorporation of the polyesters (hereinafter referred to organic solvent (e.g., n-hexane, cyclohexane, benzene,

as polymer(s) M") produced by the use of the glycol [I] as toluene). In this case, the polymer is washed with water under the whole or main part of the glycol component into base reflux in order to remove a trace of halogen compound inpolyesters prepared by ordinary procedures in the melt state cluded therein.

induces gradually the redistribution and finally afiords Decomposition or elimination of the tertiary amino group copolyesters which are not so different in structure from the does not occur even in the ester exchange process or the polyesters obtained in the said copolymerization process. The

extent of redistribution is controllable by the time during fected in the melt state at a higher temperature, and the obwhich the melt state is maintained. Compared with the tained polymer M is scarcely colored. Particularly in case of copolymerization process, the blending process is highly adthe process with the dicarboxylic acid halide, there is obtained vantageous in the secured introduction of a desired amount of the polymer M excellent in whiteness the glycol [l i.e., the tertiary amino group as the dye-site, The thus produced polymer M is materially a polyester. into polyesters. In this connection, it may be noted that the When, however, the ester exchange process is applied for its solubilities of the polymers M and the base polyesters for each Production, the ester exchange rate of the g y 1 is late other are excellent and no anxiety of separation of the blended and, therefore, the h r bond formed a th r sul f id polyesters into each component is present. The copolymerizareaction is partly present, usually atthe rate of about one bond tion using the glycol [l] as the whole or main part of the glycol per l0 ester bonds, in the product. In case of the direct component takes a relatively long time for completion but can esteriftcation process, the product has extremely few ether ultimately yield the polymer M wherein all or most of the embonds. In case of the process with the dicarboxylic acid hulide, ployed glycol [ll is incorporated as the glycol unit. For inno ether bond is included. The ultimate molecular weight of stance, the reaction of the glycol [l ]dimethyl l] (DMT) afthe polymer M is 5,000 to 6,000 in the ester exchange process, fords the polyester according to the following formulae: 3,000 and 8,000 respectively in direct esterification process CHzN i H-(OCHiCHfl DOCH2| CH20(CH2CHzO) -H+DMT R1 CHiN R2 -(OCH2CH2),,OCH2(|JOH2O(CH2CHzO) CO'CO- R3 D In view of the preference of the blending process, it will be the absence and presence of a catalyst, and about 9,000 in the hereinafter illustrated more in detail. process with the dicarboxylic acid halide.

Production of polymers M: Blending procedures:

Tl-le polymer M is produced, for instance, by heating a dicarboxylic acid in the form of lower alkyl ester with the glycol [l] in the presence of an ester exchange catalyst (e.g., zinc acetate), and, after removal of the byproduced lower alkyl alcohol, heating the resultant dicarboxylic acid ester of the glycol [11 in the presence of a polymerization catalyst (e.g., germanium dioxide) under reduced pressure. Examples of the dicarboxylic acid are aliphatic dicarboxylic acids (e.g., adipic acid, sebacic acid), aromatic dicarboxylic acids e.g., terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid) and their mixtures. Of these, the most suitable are terephthalic acid and isophthalic acid. The glycol [11 is normally employed in a two or three time molar amount to the dicarboxylic acid in its lower alkyl ester form. The reaction for 1. The fully dried pellets or powder of the polymer M are ester exchange is in most cases accomplished at 160 to 220 admixed with the pellets or powder of the base polyester, and

As the base polyester, there may be used polyethylene terephthalate or copolymerized polyesters wherein the ethylene terephthalate unit is present not less than mol%.

5 Examples of the monomers to be copolymerized with ethylene terephthalate are isophthalic acid, p-hydroxybenzoic acid, polyalkylene oxide, etc. In general, the use of the copolymerized polyesters as the base polyester is preferred, because they realize the better improvement in dyeability in the identical mixing ratio.

For blending the polymer M into the base polyester such as polyethylene terephthalate, there may be adopted various procedures, of which typical ones are as follows:

direct esterification process in which the polymerization is efthe mixture is melted and extruded by an extruder to shape films or filaments.

2. The fully dried polymer M is blended with the base polyester in the melt state and formed in pellets. The resultant pellets are dried, melted and extruded to obtain shaped products. In alternative, the blended polymer in the melt state may be as such extruded without the said intermediary formation in pellets.

3. The polymer M is incorporated into the polymerization mixture at the terminal period of polymerization for the base polyester and blended in the melt state, Then, the resultant blended polymer is formed in pellets or directly shaped.

Common to these procedures, the blending proportion of the polymer M and the base polyester can be appropriately decided, and the use of the polymer M in such an amount that 50 to 300 millimol of the tertiary amino group are present in 1 kg. of the blended polymer is favored for improvement of the dyeability of the base polyester without losing its physical characteristics.

In any of the above processes, the treatment of the shaped products with such acid chlorides as hydrogen chloride, phosphorus oxychloride, acetyl chloride, benzoyl, chloride will result in more excellent improvement of the dyeability.

The tertiary amino group originating in the glycol [11 is extremely stable and hardy affected in the course of polymerization, blending and Shaping. Thus, the polymer, the blended polymer or the shaped product from the polymers shows practically negligible coloration without using any coloring inhibitor. When desired, however. coloring inhibitors as well as any other additives such as delustering agents, stabilizers and ultraviolet absorbers may be incorporated into the polyesters under blending or shaping.

As illustrated above, the polymer M is useful as a blend material into various kinds of linear polyesters. In addition, it can be used as a blend material into polymers other than linear polyesters, an adhesive, a coating material and so on.

Practical and presently preferred embodiments of the present invention are shown in the following examples. In these examples, parts are by weight. The reduced viscosity (nsp/C) are determined at 30 C. in C=0.4 g./dl. using a mixture of phenol and tetrachloroethane (6:4) as the solvent.

EXAMPLE 1 In a reactor, dimethyl terephthalate (1 mol), the glycol of the formula:

HO CHzC CHzOH EXAMPLE 2 In a reactor, dimethyl terephthalate (1 mol), the glycol of the formula:

(2.5 mol) and zinc acetate (0.1 percent for the amount of dimethyl terephthalate) are charged, and the resultant mixture is heated at l97.5 C. for 60 minutes while removal of the produced methanol and then at 2 l 8 C. for 60 minutes. After heating up to 255 C. the pressure is reduced gradually to 0.03

mm. Hg in about 30 minutes. Heating is continued for 3 hours, during which excess of the glycol is distilled off to give yellow polymer (hereinafter referred to as polymer B"). Softening point, 76 to C. 'nsp/C=0.082.

EXAMPLE 3 In a reactor, dimethyl terephthalate (1 mol), the glycol of the formula:

CH2N(CaH1)2 HO CHzC CHzOH EXAMPLE 4 In a reactor, dimethyl terephthalate (1 mol), the glycol of the formula:

(lll2N((lill lIOCIlzCOIhOll (2.5 mol) and zinc acetate (0.l percent for the amount of dimethyl terephthalate) are charged, and the reaction mixture is heated at l97.5 C. for 60 minutes while removal of the produced methanol and then at 218 C. for 120 minutes. The pressure is reduced gradually to 0.03 mm. Hg in about 30 minutes while keeping the temperature at 218 C. The reaction mixture is further heated at 255 C. for 8 hours to give pale yellow polymer (hereinafter referred to as Polymer D"). Softening point about 30 C. nsp/C=0.08 1.

EXAMPLE 5 In a reactor, terephthalic acid (83 parts) and the glycol of the formula:

([JH2N(C2H5)2 HO CHzCIJOHZOH l 10 parts) are charged, and the resultant mixture is heated at 210 C. for 2 hours, during which the produced water is distilled out. After the temperature is raised to 230 C. while reducing the pressure gradually to 0.1 mm. Hg, polycondensation is carried out for 1 hour to give pale yellow polymer (hereinafter referred to as polymer E"). Softening point, 80 to C. 1 sp/C=0.08.

EXAMPLE 6 As in example 5, terephthalic acid (83 parts) and the glycol of the formula:

(127 parts) are reacted to give pale yellow polymer (hereinafter referred to as "polymer F"). Softening point, 55 to 62 C. nsp/c=0.08.

EXAMPLE 7 A solution of the glycol of the formula:

(43.6 parts) and sodium hydroxide (200 parts) in water (2,000 parts) is mixed with a solution of terephthaloyl dichloride (50.8 parts) in benzene (l parts) at room temperature for about 30 minutes while stirring. After recovery of the benzene, the reaction mixture is filtered to collect white solid, which is washed with water while refluxing and dried to give white polymer (hereinafter referred to as polymer G") in about 95 percent yield. Softening point, ll0 to 120 C. 'qsp/C=0.l l.

EXAMPLE 8 EXAMPLE 9 As in example 8 polyethylene terephthalate-isophthalate (the molar ratio of terephthalic acid and isophthalic acid =9: l 1 sp/C=0.750) (382 parts) is blended with polymer B (17.9

parts) to give a blended product having a good tone of color ('qsp/C=), which is spun, drawn and thermoset to give fibers.

EXAMPLE l0 Polyethylene terphthalate-isophthalate nsp/C=0.750) the molar ratio of terephthalic acid and isophthalic acid=9:l) (373 parts) and polymer D (26.6 parts) are charged in an autoclave, wherein the air is substituted with nitrogen. The mixture is blended well at 265 C. for minutes in nitrogen stream, taken out from the autoclave and pelletized. The blended polymer having a good tone of color melts at 240 C. and has nsp/C=0.560. The polymer is spun, drawn and thermoset to give fibers.

EXAMPLE 1 l Polyethylene terephthalate (nsp/C=0.750) (377 parts) and polymer C or F (23.2 parts) are charged in an autoclave, wherein the air is substituted with nitrogen. The mixture is blended well at 280 C. for 20 minutes in nitrogen stream, taken out from the autoclave and pelletized. The blended polymer having a good tone of color melts at 240 C. and has nsp/C=O.528. The polymer is spun at 270 C., drawn and thermoset to give fibers.

, EXAMPLE l2 Polyethylene terephthalate (nsp/C=0.750) (382 parts) dried previously at 165 C./l mm. Hg for 16 hours and polymer B, E or G (l7.9 parts dried previously at room temperature /0.l mm. Hg for 16 hours are blended well in a short time. The blended polymer is melt-spun at 270 C. with an extruding spinner. The spun filaments are drawn at C. four times and therrnoset at 180 C. for 5 seconds.

EXAMPLE l3 Dimethyl terephthalate (9 parts), dimethyl isophthalate (1 part) and ethylene glycol (25 parts) are reacted for transesterification (200 C., l hour) and polymerized (275 C.,/0.03 mm. Hg, 2 hours) in a conventional manner in the presence of zinc acetate and germanium dioxide. Just before completion of the polymerization, the reactor is flushed with nitrogen to atmospheric pressure and the temperature is decreased to 265 C. The resultant polymer is combined with polymer C (7 percent for the amount of the resultant polymer) dried previously at room tremperature/0.l mm. Hg for 16 hours, and the resultant mixture is blended well at the same temperature for 10 minutes and under reduced pressure for 10 minutes. The blended polymer is taken our from the reactor and pelletized. The polymer having a favorable tone of color melts at 239 C. and has 'nsp/C=0.50. The polymer is treated as in example 8 to give fibers.

EXAMPLE 14 All the fibers obtained in examples 8 to 13 show the same degree of coloration as wool, and it is confirmed that more than 90 percent of the tertiary amino group for the calculated amount has been introduced stably.

These fibers are dyed under the following dying conditions and found to be fast dyed in more than mediate shade Dying conditions Formic acid 5; OWF

Liquid ratio lzSU Temperature, period for dying |zoc.. l hour Suminol miling yellow MR Suminol miling brown 3 G Suminol first blue BR conc.

Suminol first cynnin green G Suminol levelling brilliant red SJB Suminol levelling violet 38 Example l5 Dimethyl terephthalate (94 parts), dimethyl isophthalate (6 parts), ethylene glycol parts) and the tertiary amino group-containing glycol as shown in table I are charged in a reactor, and the resultant mixture is subjected to the transesterification reaction at 200 C. for minutes in the presence of Zn(OAc) '2H 0(0.54 part). The temperature is gradually raised up to 255 C., and the pressure is gradually reduced to 0.03 mm. Hg in about 20 minutes at the same temperature. The polymerization is efiected on the conditions for 3 hours. The properties of the polyesters thus obtained are shown in the following table:

TABLE Copolymerized component Polymer Amount MJ. Structure (parts) Color tone N, percent 1; sp/C. C.)

CH2N(C2H5)2 IIO CII C CH OH 3. 9 Slightly yellow 0. 144 0. 311 .257

C HEN C3111):

4. 3 Very slightly yellow 0. 0.300 253 TABLE :Qsmt'tnued l Copolymerized component Polymer Amount M.P. Structure (parts) Color tone N, percent 1; sp/C. C.)

CHiN (OJ-I02 HOCHzCCHgOH d0 0.174 0.801 250 CHzN (CaH1)2 HOCHZCCHzOH 3.2 .do 0.121 0.352 248 CHzN (03 02 CHzN (C4HD)2 H 0 CHZCHQ pO CHzC CH CH2GH20 q 8- 5 Yellow 0. 260 0. 370 245 This compound is prepared by reacting the glycol of the for- 20 R1 mula: CHQN/ H-(O CH2CH2)p O CHM]? CHzO-(CHzCH2O) H cmmoim V a 7 7 HO OHZC CHZOH wherein R and R are each a lower alkyl group or, when taken together, they represent a lower alkylene group, R is a lower alkyl group of a group of the formula:

in which R, and R are each as defined above and p and q are each zero or a positive integer not more than 10.

2. A blended polyester comprising a base polyester and the linear polyester according to claim 1 said base polyester being polyethylene terephthalate or a copolymer containing not less than mol% of ethylene terephthalate unit.

i i t t 

2. A blended polyester comprising a base polyester and the linear polyester according to claim 1, said base polyester being polyethylene terephthalate or a copolymer containing not less than 80 mol% of ethylene terephthalate unit. 